During the operation of a wind turbine in cold weather, it is very likely that ice may be formed on the surface of wind turbine blades due to freezing of water on the cold surface. The accumulation of ice on the surface can result in undesirable consequences. For example, a change in the profile of the wind turbine blades due to the accumulation of ice reduces the lift-drag ratio of the airfoil which can result in a decrease in the speed of rotation of the wind turbine. When this happens, the wind turbine is unable to obtain optimal speed and efficiency of the wind turbine is reduced. In addition, the weight of the ice accumulated on the wind turbine blades would add weight to the blades and cause stress on the blades. This may result in stress failure in the blades.
There have been many attempts made to remove the ice that has accumulated on the surfaces. One of the attempts is the application of a coating that is capable of preventing adhesion of ice on the blade, e.g. Teflon® coating onto an underlying painted surface of the blade so that ice can slip off the coating and is prevented from accumulating on the surface. However, the application of the coatings can be costly and repeat applications of the coatings to replace worn out coatings would increase cost and downtime of the machines. In another attempt, deicing fluid has been used to dislodge the ice from the surface. However, the application of deicing fluid requires the blades to be stationery and not only does it require a downtime of the turbine, it is seemingly not effective in preventing the accumulation of ice on the blades. Yet another attempt of deicing wind turbine blade is the installation of heating panels on the blade to melt the ice. However, this method affects the aerodynamics of the blade and hence the efficiency of the blade and is expensive and difficult to maintain.
The present invention aims to provide a wind turbine blade capable of deicing ice accumulated on it without the disadvantages discussed above.